U.S. Pat. No. Re. 29,426 to Giroux discloses a safety switch for automatically de-activating a boat engine in the event a cord attached to the boat operator becomes separated from the safety switch. One instance of this happening would occur, for example, if the boat operator were thrown overboard and the cord were forcibly removed from the safety switch.
The safety switch disclosed in the Giroux patent also allows the boat operator to de-activate the boat motor in other than an emergency situation. By pressing a push button actuator, the boat operator can move a contact to a position to bridge two switch terminals coupled to the motor ignition circuit and thereby deactivate the boat motor. The safety switch uses two spring mechanisms within a safety switch housing. A first spring moves the contact to bridge the ignition circuit terminals in the event the cord is disconnected from the switch and a second spring biases the terminals away from the closed position in a way which can be easily overcome by user activation of the push button in the event it is desired to de-activate the boat motor.
One difficulty with the safety switch disclosed in the Giroux patent is that the boat motor cannot be easily re-activated once the cord is disconnected from the switch. To re-activate the boat motor, the operator must either reconnect the cord to the switch or pull the push button actuator while operating the motor.